Glass fiber-reinforced crystalline resin compositions obtainable by blending glass fibers with crystalline resins (crystalline synthetic resins) such as polyethylene, polypropylene, polybutene-1, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyamide, and polystyrene are superior in strength and rigidity to unreinforced crystalline resins and have recently been expected for the expansion of their applications.
However, because of problems such as the affinity between such crystalline resins and glass fibers, the orientation of glass fibers, and so on, glass fiber-reinforced crystalline resin compositions have drawbacks such as that strength or rigidity is not increased sufficiently and that surface roughness is produced. The varying of the form of glass fibers or the type of a sizing agent can somewhat improve such drawbacks, but it does not show remarkable effects.
Patent Literature 1 indicated below has proposed to improve the surface properties and mechanical properties of a molded article by incorporating an aromatic phosphate metal salt, or the like into a resin composition containing a polyolefin, a polybutene-1, and glass fibers, but in the event that an aromatic phosphate metal salt is added as a nucleating agent directly to a crystalline resin, the effect thereof is still insufficient.
Moreover, Patent Literature 2 indicated below has proposed to improve the surface properties and mechanical properties of a molded article by incorporating an aromatic phosphate metal salt as a nucleating agent to a glass fiber sizing agent, but further improvement has been awaited.